Efficiently finds shapes that are affected by a change when the shape's where clause has field = const in it.

Data is stored in the Filter's eq_index_table ETS table with keys of the form: {condition_id, field, value} -> {type, next_condition_id}

The type is stored to know how to parse values from records. The next_condition_id points to a WhereCondition for the remaining conditions of the where clause.

Additionally, the field type is cached at: {:type, condition_id, field} -> type This enables O(1) type lookup for parsing record values.